The economy is booming, and Americans are no longer clamoring for tax relief. Congress passed a modest tax cut two years ago; most state and local governments have slashed taxes as well. And President Clinton has apparently mastered the art of making Republican tax cutters look like Medicare-busters, Social Security-destroyers and debt-expanders.

But that hasn't stopped them, not even close. On Capitol Hill, Republicans are once again staking their political futures on massive tax cuts, as they have done for the last two decades. Don't try to analyze it too much, analysts say. This is what Republicans do.

"God put Republicans on earth to cut taxes," said Marshall Wittmann, a director of congressional relations for the conservative Heritage Foundation. "It's the last major issue that separates them from Democrats. If they give in on taxes, there's no difference anymore."

The rhetoric of the issue has changed a bit; because it's hard to argue these days that tax cuts are needed to spur economic growth, Republicans now tend to describe them as a moral obligation. The politics of the issue has changed too, now that the tax revolt fever that swept America during the malaise days of the late 1970s has given way to the good times of the late 1990s. But the Republican commitment remains the same. In fact, as Clinton has neutralized traditional GOP issues such as crime and welfare by shifting to the right, many Republicans have decided that taxes may be the last unifying issue for their increasingly fractured party.

The question is, is it a winning issue? House Budget Committee Chairman John R. Kasich (R-Ohio), one of the most fervent tax cutters in Congress, abandoned his failing presidential bid this week. In a Harris poll last February, only 12 percent of the electorate named taxes as one of the two most important issues facing the nation. In a CBS-New York Times poll, voters who were asked to rank the importance of six issues facing Congress put tax cuts dead last, behind education, Social Security, health care, Medicare and poverty. With more money in their pockets, voters no longer seem so angry about the share they send to Washington.

Still, voters have always preferred low taxes to high taxes, and Republicans have enjoyed some of their greatest electoral successes by tagging Democrats as tax-and-spend liberals. At a time when the GOP is divided by issues such as abortion, gun control and foreign policy, and when Democrats must square their doom-and-gloom scenarios with a projected budget surpluses of nearly $3 trillion over the next decade, Republicans are turning to the tax issue like an old and reliable friend.

"In the strong economy, the issue has lost a lot of potency," said Claremont McKenna College professor John Pitney, an expert on congressional politics. "But you have to remember, for a generation of Republican leaders, it's been the central element of the party doctrine."

Those GOP leaders are now crusading to return a good chunk of the surplus to taxpayers. House Ways and Means Committee Chairman Bill Archer (R-Tex.) has unveiled a broad-based $864 billion tax cut plan, the largest to surface in Congress since 1981, and Senate Finance Committee Chairman William V. Roth Jr. (R-Del.) has proposed a $792 billion reduction. Senate Majority Leader Trent Lott (R-Miss.) says the issue is "critical" to the GOP agenda; House Speaker J. Dennis Hastert (R-Ill.) warns darkly that if Congress does not use the surplus for tax cuts, it will probably be wasted on unnecessary government spending. A few Republicans on the right, including presidential candidate Steve Forbes, have complained that the cuts should be even deeper.

By contrast, Clinton and most congressional Democrats are pushing a less sweeping $250 billion tax cut plan targeted at the poor and middle class, vowing to reserve the rest of the surplus for debt reduction, Medicare and Social Security. They are gleefully pummeling the GOP plans as risky and extreme, warning that the lost revenue would endanger Head Start, the FBI, national parks, national defense and just about every other popular government activity. They say Republicans are just pandering to their wealthy donors and their conservative base, claiming that the bulk of the GOP tax benefits would go to upper-income Americans.

"They're being completely irresponsible," said Rep. Sander M. Levin (D-Mich.). "I guess their pollsters told them they don't stand for anything these days, so they need to grab the tax issue and run."

Some Republicans also acknowledge the political calculations involved; they say they need to outflank Clinton on taxes if they want to maintain an identity of their own. On a policy level, they say, conservatives have already won the tax debate, just as they won the welfare debate and crime debate when Clinton parted ways with the left wing of his party. But on a political level, now that Democrats no longer reflexively oppose tax cuts, Republicans have been pushed even farther to the right. "We're dealing with the politics of plenty, so this probably isn't the right moment for big tax cuts," said Rep. Mark Sanford (R-S.C.), a deficit hawk who says he will probably support the Archer plan anyway. "But a lot of folks on the right flank are saying: `Where's my Republican Party?' This is one way of saying: `Hey, we're still here.' "

But Archer, Roth and other GOP leaders say their tax plans are not about politics; they're about people, about values. Archer, who is retiring next year, called his plan the Financial Freedom Act of 1999, and unveiled it at a news conference surrounded by minority families.

The vast size of the American tax burden, he said, is morally wrong, an affront to liberty. It forces parents to work too hard to make ends meet, and prevents them from spending enough time with their kids. It transfers too much power to Washington bureaucrats. It is not fair to "wonderful people" like Brenda LeSienne, he said, pointing at a woman named Cathy Lazano.

Wittmann, the Heritage Foundation analyst, notes that many Republicans began to emphasize the moral aspects of tax policy around the time that polls began to signal increased voter concern about "values." But notwithstanding his use of strangers as human props, Archer obviously believes in cutting taxes on a visceral level. And so do most of his GOP colleagues.

"This is the defining difference between Democrats and Republicans," Archer said. "We want to downsize the power of government and upsize the power of people. They think government bureaucrats can spend the people's money more wisely than the people themselves."

In any case, the outcome of the political standoff will have huge policy consequences for Medicare, Social Security, domestic programs and the tax bite in American paychecks. That's a big deal for Americans such as Jorge Lazano, the man whose wife was misidentified at Archer's news conference. Lazano took a $70-a-week job as a dishwasher after he emigrated from Bolivia in 1972; now he makes more than $100,000 a year running a high-tech firm in Virginia. Without a hint of irony, he says he had an easier time saving money in his restaurant job.

"We're supposed to be living the American dream, but we're paying too much in taxes," he said. "We want the politicians to help us. We don't care if they get our names right."